Lahan climate
Lahan (Nepal) has a monsoon-influenced humid subtropical climate (Köppen Cwa). The average temperature over the year is 26 °C78 °F, and about 1,104 mm43 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Lahan climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin |
|---|---|---|---|---|
| Jan | 2373 | 948 | 1661 | 80.3 |
| Feb | 2781 | 1355 | 2068 | 120.5 |
| Mar | 3392 | 1864 | 2678 | 170.7 |
| Apr | 38101 | 2374 | 3187 | 331.3 |
| May | 39102 | 2679 | 3290 | 893.5 |
| Jun | 3799 | 2781 | 3290 | 1766.9 |
| Jul | 3392 | 2679 | 3085 | 29612 |
| Aug | 3290 | 2678 | 2984 | 2198.6 |
| Sep | 3188 | 2476 | 2882 | 1987.8 |
| Oct | 3086 | 2169 | 2578 | 502.0 |
| Nov | 2781 | 1560 | 2171 | 20.1 |
| Dec | 2374 | 1151 | 1763 | 30.1 |
| Year | 39102 | 948 | 2678 | 1,10443 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 49% | 35% | 3.1 | 10:38 |
| Feb | 41% | 30% | 4.3 | 11:13 |
| Mar | 31% | 33% | 5.5 | 11:56 |
| Apr | 31% | 36% | 6.2 | 12:46 |
| May | 43% | 47% | 6.1 | 13:27 |
| Jun | 58% | 68% | 5.3 | 13:49 |
| Jul | 79% | 83% | 4.6 | 13:40 |
| Aug | 83% | 79% | 4.9 | 13:04 |
| Sep | 83% | 67% | 4.5 | 12:16 |
| Oct | 74% | 32% | 4.5 | 11:29 |
| Nov | 62% | 14% | 3.9 | 10:48 |
| Dec | 55% | 24% | 3.0 | 10:28 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Lahan is like
The warmest month is June, with an average high of 37 °C99 °F and a low of 27 °C81 °F. The coldest is January, when highs average 23 °C73 °F and lows 9 °C48 °F. There is a clear seasonal cycle, with 16.6 °C30 °F between the average temperature of the warmest and the coolest month.
It is wet, with about 1,104 mm43 in of precipitation per year. The wettest three-month stretch is July–September, which brings 65% of the annual total. Months with less than 20 mm0.8 in on average: November–March. The wettest month is July (296 mm12 in), the driest is November (2 mm0.1 in).
Relative humidity ranges from 31% in March to 83% in September. The clearest skies (lowest average cloud amount, 14%) are typical of November. Average wind speed near the ground ranges from 4 km/h (3 mph) in November to 9 km/h (6 mph) in July. Daylight lasts from about 10.5 hours in December to 13.8 hours in June.
Best time to visit Lahan
Based on these averages, the most comfortable months for sightseeing and outdoor activities are November–February: average highs of 23 °C73 °F to 27 °C81 °F with 2 mm0.1 in to 12 mm0.5 in of precipitation per month.
The most challenging month is July, which is hot, with average highs of 33 °C92 °F, very wet (296 mm12 in) and humid (79% relative humidity).
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Lahan
- Winter (December–February) — highs 2373 to 27 °C81 °F, lows 948 to 13 °C55 °F, about 8 mm0.3 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an extra layer for the cooler mornings and evenings.
- Spring (March–May) — highs 3392 to 39 °C102 °F, lows 1864 to 26 °C79 °F, about 47 mm1.8 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water.
- Summer (June–August) — highs 3290 to 37 °C99 °F, lows 2678 to 27 °C81 °F, about 230 mm9.1 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water and a good rain jacket or umbrella and quick-drying shoes.
- Autumn (September–November) — highs 2781 to 31 °C88 °F, lows 1560 to 24 °C76 °F, about 83 mm3.3 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses.
How Lahan compares
Compared with Janakpur, about 55 km to the west, Lahan has practically the same average temperature and receives a similar amount of precipitation. The difference is largest in May (0.8 °C1.4 °F cooler).
Of the 13 places in Nepal covered by World Climates, Lahan is the 7th warmest by annual mean temperature and the 12th wettest by annual precipitation. See all of them on the Nepal climate page.
Places in other countries with the most similar temperature and rainfall pattern: Saharsa (India, Cwa), Bagaha (India, Cwa) and Bettiah (India, Cwa).
Nearby places
- Janakpur 55 km · 26 °C78 °F · 1,145 mm45 in
- Dharan 80 km · 24 °C76 °F · 1,231 mm48 in
- Biratnagar 84 km · 26 °C79 °F · 1,394 mm55 in
- Saharsa 95 km · 26 °C78 °F · 1,164 mm46 in
- Muzaffarpur 127 km · 26 °C79 °F · 1,060 mm42 in
- Purnia 144 km · 25 °C78 °F · 1,348 mm53 in
- Begusarai 149 km · 26 °C79 °F · 1,026 mm40 in
- Mothihari 156 km · 26 °C78 °F · 1,134 mm45 in
Frequently asked questions
What is the warmest month in Lahan?
June is the warmest month in Lahan, with an average high of 37 °C (99 °F) and an average low of 27 °C (81 °F).
What is the coldest month in Lahan?
January is the coldest month, with an average high of 23 °C (73 °F) and an average low of 9 °C (48 °F).
When does it rain the most in Lahan?
July is the wettest month with about 296 mm (11.6 in) of precipitation; November is the driest with about 2 mm (0.1 in).
What is the best time to visit Lahan?
Judging by long-term averages, the most comfortable months are November–February.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.